Oxygenated organic polymers



Patented Feb. 14, 1950 OXYGENATED ORGANIC POLYMERS Donald J. Loder andWilliam F. Gresham, wu-

mington, Del., assignors to E. I. du Pont de Nemonrs & Company,Wilmington, Del., a corporation of Delaware No Drawing. Originalapplication May 6, 1341, Serial No. 392,128. Divided and thisapplication December 30, 1944, Serial No. 570,172

7 Claims.

This invention relates to a process for the preparation of oxygenatedorganic polymeric compounds, and more particularly to their preparationfrom 1,3-dioxolane and polyhydric compounds and to the resultingpolymers. This application is a division of my copending application392,128, filed May 6, i941, and now abandoned.

The copending application of W. F. Gresham, S. N. 392,124, filed May 6,1941, and now Patent Number 2,394,910, issued February 12, 1946,discloses that 1,3-dioxolane. a -membered ring, can be treated to givepolymers ranging in properties from mobile liquids to cold-drawablecrystalline-like solids. That invention is entirely contrary to theteachings of the art which insists that 5-membered rings are stable andconsequently unpolymerizabie. As a corollary to the prior art teaching,it would be logical to assume that a stabile 5-membered ring such as1,3-dioxolane would not readily break and enter into reactions to formpolymeric compounds.

In contradistinction to the teachings of the art, thepresent inventionprovides new reaction products obtained from 1,3-dioxolane and itssubstitution products with other organic compounds. Another object ofthe invention is to provide new compositions of matter from1,3-dioxolane, or its substitution products, and polyhydric compounds.Yet another object is to provide a process for the interaction of1,3-dioxolane and its substitution products with polyhydric alcohols,their ethers, esters, and other derivatives, said derivatives containingat least one free hydroxyl group. Another object of the invention is toprovide reaction conditions and catalysts for such reactions wherebyvaluable products are obtainable. Other objects and advantages of theinvention will hereinafter appear.

Valuable products are obtained in accord with the invention by reacting1,3-dioxolane with poly v c compounds, such, for example, as the:

(ll Polyhydric alcohols including especially the glycols and glycerols.

(2) Derivatives of the polyhydric alcohols which contain at least onefree hydroxyl group.

(3) Carbohydrates such as the monosaccharides, the dlsaccharides, andthe polysaccharides as defined by Booth, "Chemical Dictionary," 1937,pages -8.

The products of the invention are 01' relatively high molecular weightand will hereinafter be referred to as polymers, which term will includeall products containing at least two 1.3-dioxolane residues and at leastone alcohol residue. For to (Cl. 26H) example, the polymers resultingfrom the reaction of 1,3-dioxolane with ethylene glycol will contain atleast two 1,3-dioxolane residues, each having the formula -CH2OCH2CH2Oand at least one glycol residue which may be either CHaCHzO orHOCHzCI-I2O, the latter occurring on the end, the former within themolecule. The polymers of the invention are believed to have a linearform and there is good theoretical foundation for this assumption; theformulas given below. therefore, describe the products by way ofillustration and not by way of limitation.

The invention may be illustrated by the reaction of 1,3-dioxolane andethylene glycol in accord with the equations:

(1) HaC-O In (1) 1,3-dioxolane reacts with ethylene glycol to formdi(beta-hydros ethylliormal, while in reaction (2) the forma ion ofdi(beta-hydroxyethoxymethoxyethyllfdrmal is illustrated by the reactionoi three moles of l,3-dioxolane with one mole of ethylene glycol, bothcompounds being liquid polymers.

The alcohols, their ethers and esters. may be reacted in accord with theprocedural details more fully particularized hereinafter, with1,3-dioxolane has the chemical formula with numbering as shown:

a lie-0 and may be obtained by reacting formaldehyde with ethyleneglycol. Products with substituents in the 2 position can be readilyobtained by reaction of ketones or other aldehydes either all-- phaticor aromatic with ethylene glycol. Thus. by way of example, manycompounds are obtained which may be employed in accord with theinvention. such as Z-methyl-LS-dioxolane, 2-ethyl-l,3-dioxolane,2,2-dimethyl-l, 3-dioxolane, 2,2-diethyl-L3-diosolane,2-phenyl-l,3-dioxolane, 3,2 methylphenyl 1,3 dioxolane, and higherdioxolanes substituted in like manner which may, for example, beobtained from ethylene glycol and acetaldehyde, propanal, acetone,diethyl ketone, benzaldehyde, methyl phenyl ketone, and highersubstituted aldehydes respectively. The invention likewise contemplatesthe use of dioxolanes substituted in the 4 and/or positions. Thesedioxolanes are obtained by the interaction of substituted 1,2-glycolswith aldehydes, for example, 1.2-propylene glycol-Hormaldehyde will gived-methyl-Lil-dioxolane and similarly the following dioxolanes can bereadily prepared from formaldehyde and the corresponding glycols:4-ethyI-L3-dioxolane. e-lii'ol yl-l, 3-dioxolane,4,5-dimethyl-L3-dioxolane, and the like. The polymers of 1.3-dioxolaneas described in the copending application 01W. F. Gresham, S. R.392,124, filed May 8, 1941, can likewise be reacted with thehydroxyl-containing compounds to give higher molecular weight products.

The above dioxolanes may be reacted with bydroxyl-containing compoundsand more particularly by way of example the monohydrlo alcohols such asmethanol, ethanol, nand iso-propanol, nand iso-butanol, and the higherstraight and branch chained monohydric alcohols as well as mixtures ofalcohols, such, for example, as those obtained by the catalytichydrogenation of carbon oxides under elevated temperatures and pressuresand similar mixtures of alcohols, such as are obtained by the catalytic.hydrogenation of oils or fats (consisting mainly of alcohols of theempirical formula CsHnOH to Ciel-1110K, in which alcohols about 50% ofdodecyl alcohol is generally present). There likewise may be used inaccord with the invention the higher straight and branch chainedalcohols, such, for example, as hexyl, heptyl, octyl, nonyl, decyl,dodecyl, tetradecyl, cetyl, carnaubyl, ceryl, melissyl, tarchonylalcohols, and the like. Polyhydrlc alcohols may likewise be employed.such, for example, as ethylene glycol and the vicinal glycols generally;1,2-propylene glycol, 1,2-butylene glycol, 2,3-butylene glycol, and thehigher polyhydric alcohols, such as, for example, trimethylene glycol;diethylene glycol, triethylene glycol, tetraethylene glycol,hexamethylene glycol, dipropylene glycol, and the higher polyhydricalcohols, such as glycerol. erythritol, pentitols, hexitols, hepitols,arabitol, mannitol, sorbitol, dulcitol, and so forth. Alkyl ethers ofthe above designated po yhydric alcohols are likewise included, such,for example, as the monoalkyl ethers of ethylene glycol, diethyleneglycol, propylene glycol, and more specifically the monomethyl ether ofethylene glycol, monoethyl ether of ethylene glycol, monomethyl ether ofglycerol; the monoesters of the above polyhydric alcohols such as, forexample, ethylene glycol. propylene glycol, and glycerol mono acetate,propionate, stearate, oleate, etc., which contain a free hydroxyl groupand in fact any substituted polyhydric alcohol may he used providedthere is present at least one free hydroxyl group.

In addition to the more or less simple monohydric and po yhydricalcohols above referred to as suitable for use in the reaction, theremay likethis group are the cellulose derivatives. as. for example,methyl, ethyl, and propyi cellulose. partially etheriiied, and celluloseacetate, acetopropionate, glycolate; etc., partially esterlfled.

Valuable polymers are obtainable from the reaction of large amounts at1,3-dioxolane with small amounts of the hydroxyl-containing compound.The greater the amount of dioxoiane present the greater becomes theviscosity of the polymers until solids are produced, while contrarywisethe greater the ratio of the hvdroxyicontaining compound the lessviscous will be the resulting polymer. There appears to be no limitingfactor restricting the proportions of the reactants.

The reaction between the dioxolane and by; droxyl-containing compound iseffected at tom;

peratures ranging between 80 and i300 0. and preferably between 0 and C.Atmospheric, subor superatmospheric pressures may be used, and if thelast, pressures may range between 1 and 1000 atmospheres or higher.Normally excellent results are obtained at or about atmosphericpressure. If desired, the temperature of the reaction, especially whenpolymerization is carried out at the boiling point of the reactionmixture, may be controlled by varying the pressure on the boilingreactants.

It has been found advantageous to effect the reaction in the presence ofan acidic type catalyst such, for example, as sulfuric acid, phosphoricacid; the halogen acids, such as hydrochloric acid, hydrofluoric acid(alone or with B1 5) boron fluoride (including its complexes with water,acids, esters, alcohols, and the like), paratoluene sulfonic acid,camphor sulfcnic acid, and other acid catalysts of this general nature.Friedel-Crafts type catalysts other than BF: may be used, such as A1013,AlBra. Each, and so forth, as well as inorganic acids generally andtheir acid salts such as sodium acid sulfate, sodium acid phosphate, andso forth. a

The catalyst may be supported or not or inert supports such as charcoal,silica gel (which alone is a catalyst for the reaction), kieselguhr, andso forth. Concentrations of B1 5, H1804 and similarly strong catalystsmay be extremely low; less than 0.1 and amounts down to as low as 0.00196 of the strong acid catalysthave been found suiilcient to givepolymers although high concentrations of the catalyst even equal to orgreater than the weight of the dioxolane are likewise satisfactory.

The reaction is preferably continued approximately to equilibrium inorder to obtain the above defined polymeric oxygenated organiccompounds. The reaction may then be stopped by destroying the catalyst.This may be done by removing it (in the case of silica gel, kieseiguhr,and the like) or by treating the reaction mixture with an inorganicbase, such as ammonia, alkali metal, and alkaline earth metalhydroxides, carbonates, alkoxides, and so forth or an organic base, suchas pyridine, dimethylamine, and the like. These bases are added insuillcient amounts to neutralice the catalyst when acid catalysts areused, and the unconverted reactants may be removed by distillation underreduced pressures. As soon as the catalyst has been neutralized, thereaction ceases. The neutralized catalyst may be filtered on and thepolymerized product which remains treated for the recovery of thepolymers.

In the reaction of the dioxolanes and hydroxylcontaining compounds andmore especially 1,3- dioxolane and the glycols to give polymers, thereusually will be found in the reaction mixture along with the polymer,unreacted dioxolane and glycol, together with by-products and polymerswhich it is not desired to produce. It is possible to inhibit theformation of the undesired products by carrying out the process in anintermittent or continuous manner whereby the desired polymer iswithdrawn from the reaction zone and the undesirable products, afterbeing separated therefrom, are returned to the reaction zone. By thismeans it is possible to obtain high yields of the desired polymer.

In addition to being instrumental in stopping the reaction at thedesired point, the neutralization of the catalyst tends to stabilize thepolymers. It follows, therefore, that for high temperature uses, no acidshould be present in the polymers. They should preferably be neutral oron the alkaline side.

Examples will now be given illustrating embodiments of the invention,but it will be understood that it will not be limited by the detailsthereof. Parts are by weight unless otherwise indicated.

Example 1.A reaction mixture was prepared by mixing 148 parts of1.3-dioxolane. 496 parts of glycol and 6 parts of sulfuric acid. Thiswas heated on a steam bath under a reflux condenser for 5 hours. In theinitial stages of the reaction dioxolane refluxed. After approximately 1hour, boiling ceased and the reaction mixture became somewhat viscous.The catalyst was then neutralized, to blue litmus, with a methanolsolution of sodium methoxide and the reaction product was fractionallydistilled under reduced pressure. The following materials were obtained:24.5 parts of unchanged 1,3-dioxolane, 396.5 parts of unchanged ethyleneglycol, 1405 parts of di(beta hydroxyethyl) formal, and 72.4 parts of acolorless fairly viscous liquid polymer.

Erample 2.-A mixture comprising 1110 parts of 1,3-dioxolane. 930 partsof ethylene glycol and 10 parts of sulfuric acid was processed underconditions simulating those of Example 1 with the exception that calciumcarbonate was used to neutralize the catalyst. 56"! parts of glycol anddi(beta hydroxyethyl) formal was distilled off at 2 mm. leaving 1325parts of polymer. This polymer gave on analysis the following data:hydroxyl No. 591; refractive index at 25 C., 1.4510; and density at 250., 1.1665.

The following examples illustrate the preparation of higher molecularweight polymers. Reaction conditions were the same as described above.The sulfuric acid catalyst was converted to ammonium sulfate by theaddition of anhydrous ammonia and aqueous caustic was then added to givefrom 1 to 10% excess. In order to obtain the high molecular weightpolymers, it is advisable to add the anhydrous ammonia before theaqueous base in order to eliminate the possibility of water combiningwith the polymer. The molecular weights were determined by the solutionmethod.

Example 3.Reaction mixture:

740 parts 1,3-dloxolane 62 parts glycol 3.5 parts H2804 Product liquid.Molecular weight, 440.

Example 4.-Reaction mixture:

740 parts 1,3-dloxolane 15.5 parts glycol 3.5 parts H280! Product:

102.5 parts unchanged 1,3-dioxolane 620 parts polymer, a solid meltingat 44-50 C.

Molecular weight, 710.

Example 5.--Reaction mixture:

740 parts 1,3-dioxolane 7.8 parts glycol 3.5 parts H280 Product 88 parts1,3-dioxolane 649 parts polymer. Colorless solid melting at 49-54" C.Molecular weight, 939.

Example 6.--Reaction mixture:

740 parts 1,3-dioxolane 1 part glycol 3.5 parts H2804 Product partsunchanged 1,3-dioxolane 660 parts polymer. Colorless solid melting at52-54 C. Molecular weight, 1284.

All of the above described polymers are miscible in all proportions withbenzene, methanol, and water. They also dissolve nitrocellulose.

Example 7.A reaction mixture prepared from parts of anhydrous glucose.740 parts of 1,3-dioxolane, and 4 parts of H2804 was heated on a steambath with stirring for 5 hours. Boiling ceased at the end of 0.5 hour.Glucose dissolved yielding a homogeneous reaction mixture afterprocessing 3 hours. Sulfuric acid was neutralized to blue litmus withanhydrous NH; followed by 3.3 parts of N-OH in 12 parts H2O. At 2 mm.and C. unchanged 1,3-dioxolane, 156 parts, was stripped off. A benzenesolution of the product was filtered to remove N-SOr. Removal of benzeneat 3 mm. and 100 0. gave 677 g. of glucose-1,3-dioxolane polymer. aviscous liquid miscible with water, benzene and methanol having amolecular weight of 650.

Example 8.From equal parts by weight of 1,3- dioxolane and glucose andduplicating the conditions of Example 7, an extremely viscous liqaid wasobtained which was miscible with water, benzene and methanol and had amolecular weight of 1060.

Example 9.A mixture consisting of 9.2 parts of glycerol, 592 parts of1,3-dioxolane, and 3.4 parts of sulfuric acid was warmed until ahomogeneous solution was obtained and then heated for 5 hours on a waterbath. The catalyst was neutralized with anhydrous ammonia to blue litmusfollowed by 3.1 parts of NaOH in 10 parts of H20. Unconverted1,3-dioxolane, 151 parts. was removed under reduced pressure. A benzenesolution of the residue was treated with CO2 and filtered. Benzenediluent was removed at 2 mm. and 100 C. 444.5 parts ofglycerol-1,3-dloxolane polymer, a practically colorless solid, M. P.43-49 C. soluble in water, benzene and methanol having a molecularweight of 694 was obtained.

Example 10.-To 740 parts of 1,3-dioxolane containing 3.5 parts of H2804was added 45.5 parts of sorbitol. The mixture was warmed a few minuteswith agitation to eilect solution of 1 the sorbitol and then heatedunder a return conceased after 0.5 hour with the production of a viscousliquid. Subsequent to neutralization of the catalyst with anhydrous NH:to blue litmus followed by 3.1 parts of NaOH in 12 parts of water,unconverted 1,3-dioxolane, 172 parts, was removed under reduced pressureat about 100 C. The resulting polymer was dissolved in benzene. thesolution filtered to remove Nat-S04 and the benzene removed underreduced pressure, finally to 1 mm. and 100 C. The remaining viscouspolymer, 615 parts, solidified on standing-hydroxyl No. 172.3; molecularweight in boiling benzene, 720.

The examples which follow were carried out under conditions simulatingto those used in Example 10.

Example 11.Reaction mixture:

50.5 parts i-thiosorbitol 740 parts 1,3-dioxolane 4 parts H2804 Product:

157 parts unconverted dioxolane 612 parts l-thiosorbitol-dioxolanepolymer. Semisolid. Hydroxyl No. 210. Molecular weight in boilingbenzene, 525. Soluble in water and benzene.

Example 12.Reaction mixture:

210 parts polyvinyl alcohol 370 parts 1,3-dioxolane 3 parts H2804 257.5parts unconverted 1,3-dioxolane 289 parts ver light colored tough solidpolyvinyl alcohol-dioxolane polymer which was insoluble in water.

Example 13.Reactin mixture:

84.5 parts ethylene glycol 481 parts 4-methyl-1.3-dloxolane 2.8 partsH2504 Product:

53.3 parts ethylene and propylene glycols 107 parts 1,3-dioxolane 179parts 4-rnethyl-L3-dioxolane 127.8 parts viscous liquid polymer.

Example l4.-Reaction mixture:

248 parts ethyleneglycol 352 parts 2-methyl-L3-dioxolane 6 parts H2304Product:

271 parts 2-methyl-l,3-dloxolnne 219.5 parts glycol 46 partsdi-(beta-hydroxy-ethyl) acetaldehyde acetal (HOCH2CH20)2CHCHJ, B. P. 110C./ mm.; density at 25 C., 1.1185; refractive index at 25 C., 1.4455.Small quantit of higher polymers.

Example .-Reaction mixture:

220 parts polyethylene glycol (molecular weight in boiling benzene, 360)740 parts 1.3-dioxolane 4 parts H2804 Product:

232 parts 1,3-dioxolane 724 parts polyethylene glycoi-dioxolane polymer.Soluble in water and benzene. Hydroxyl No. 84. Molecular weight inboiling benzene. 030.

Example 16.Reaotion mixture:

15 parts bexamethylcne glycol 740 parts 1.3-dioxolane 3.5 parts 112504Product:

50 parts 1,3-dioxolane 694 parts hexamethylene glycol-dioxolane polymer.Hydroxyl No. 163; refractive index at 25 0. 1.4575; density at 25 C.,1.170; molecular weight in boiling benzene, 694.

Example 17.Reaction mixture:

13.6 parts pentaerythritol 592 parts 1,3-dioxolane 3 parts H2804Product:

162 parts 1,3-dioxolano 443 parts pentaerythritol-1,3-dioxolane polymer,viscous liquid which solidified on standing. Soluble in water andbenzene. Hydroxyi No. 79.4; molecular weight in boiling benzene. 1150.

Example 18.Reactlon mixture:

parts 1.3-butylene glycol 740 parts 1,3-dioxolane 3.5 parts H2804Product:

135.! parts 1,3-dioxolane 152 parts 4-methyl-1,3-dioxane 575.5 partssomewhat viscous polymer. Soluble in benzene and water. Hydroxyl No.278. Molecular weight in boiling benzene, 430.

Example 19.Reaction mixture:

228 parts methoxy ethanol 740 parts 1,3-dioxolane 4 parts HzSOi Product:

Example 20.A mixture comprising 30 parts of p-hydroxy-ethyl hydroxyacetate. 740 parts of 1,3-dioxolane and 3.5 parts of sulfuric acid washeated in a water bath for 5 hours. Subsequent to neutralization tolitmus oi the catalyst with anhydrous NH; followed by 3.1 parts of NaOHin 12 parts of water, unconverted 1,3-dioxoiane, parts, was removed at 1mm. pressure and 100 C., and 604 parts of p-hydroxyethyl hydroxy acetateglycol polyi'ormal was obtained. It was a colorless viscous liquidsoluble in water, benzene and methanol. Molecular weight 721.

The compounds prepared in accord with the invention may be employed fora large number of uses. The polymers which are soluble in water aresuitable as additions to various baths for the treatment of natural andsynthetic textiles. For example, they may be employed in washing,dyeafter-treating. merccrizing, carbonizing, fulling, wetting,dispersing, emulsifying, and levelling operations. and furthermore, forimproving the fastness of dyeings to rubbing. These polymers maylikewise be used as solvents and as assistants for converting dyestufisinto pastes and 9 as emulsifying agents, for instance, for dispers ingoils, fats, and hydrocarbons.

The polymers are well adapted for use as a size, size lubricant, andwarp size plasticizer; they are likewise suitable for use as spinningbath assistants, twist setter, yarn conditioner, and may he used in theprinting oi textiles to improve fabric receptivity by treatment of theyarns or cloth either prior to or subsequent to dyeing, and as aspreading and dispersing agent for printing pastes and dyes; theylikewise are suitable for use in making fabrics impervious to oils; as asubstitute 011 size for synthetic and natural fibers; as an ingredientin mercerizing liquors; as a softener and "hand" improver for cotton,rayon, silk, wool,

and nylon; as a degumming agent for silk and wool; as a coating for theprotection of yarns during processing; as a delustering agent for rayonand silk; as a crease and crinkle-proofing agent and for use in thefulling and finishing of textiles.

In the leather, rubber, and synthetic plastics held the polymers of thisinvention may be used as plasticizers particularly for incorporationwith the more flexible polymers, in rubber protective coatings, incellulose derivatives such as cellulose acetate, cellulose nitrate,cellulose acetonitrate, and cellulose acetobutyrate, and in polyvinylacetale and polyvinyl alcohol derivatives; they may likewise be used asa preservative for rubber and for preventing coagulation of latexemulsions. They are adaptable for use as mold lubricants: dispersingagents for rubber latex; as leather processing and finishing agents; foruse in fur mordanting; as an ingredient in non-curling cellulose filmsand for rendering cellulose films, such as cellulose acetate andcellulose nitrate, non-corrosive; as wetting agents for use inprocessing natural and artificial leather; as a sealing agent for"cellophane films: and as an ingredient of adhesives with glue, forexample, for use in the leather, rubber and plastic arts generally.

The products dissolved or dispersed in water or other liquid or asprepared may likewise be used in the paper industry for increasing thewet strength of paper and cardboard: for greaseproofing paper andcardboard; as a paper size and sof tener; as a dispersing agent forpigments in paper coating; as a transparentizing agent for paper stock;as a carbon paper vehicle; and as a water soluble base for release ofdecalcomanias.

In the cosmetic iield these polymeric compounds likewise find utility asan emulsifying agent for lotions and creams, and for rendering thesematerials antiseptic; the may be employed as a base for hair dressingsand pomades; as an ingredient in permanent waving and hair conditioningtreatment; as a component of paste soaps to prevent the tendency to setor gel: as an ointment base, primarily because of their ability to givegood contact and the ease with which they are removed; and as aningredient in hand, abrasive, and antiseptic soaps.

The polymers may be used to replace vehicles used in inks; as inkreducers: as solvents for the solids used; and to prevent mold formationin ink, hectograph, and ditto pads. In the paint industry they may beused to control tack and viscosity and for dispersing, spreading,emulsifying and wetting printing pigments and pastes: as an ingredientin non-drying and slow drying oil pastes; as a substitute for the alkydresins; as an antilivering and anti-skinning agent; and they may beemployed to retard the drying of paint removers and paint solvents. Theylikewise may be used as high-boiling lacquer solvents to replace 10ether-alcohols in stains; as solvents for textile dye pastes, furniturepolish,- and the like; as a frosting inhibitor in China-wood oil:general thickener and toner; and as a solvent and softener for waxes,gums, rosin, and resins to be incorporated in paints, ink, varnish,lacquers, and the like.

The derivatives may likewise be used as a humectant in tobacco. fruits,and foods; as an air conditioning ingredient to lay dust; as a selectivesolvent for use in oil and gas purification, particularly in thepetroleum industry; as a selective absorbent of gases: as a poison gasabsorbent; and for extracting albumin from dried milk. The polymers maylikewise be employed as a dehydrating agent for alcohols; as a liquidseal in gas holders; as an anti-freeze in gas meters, mains.refrigerators, and so forth; and as a conditioning agent for plantleaves to impart gloss and fresh appearance. They may likewise be usedas gasoline stabilizers especially for tetraethyl lead to improve cetanenumber of fuels; as an ignition promoter in Diesel fuels and as a carbonand gum remover in internal combustion engines. They have found utilityas a fungicide in the prevention of mildew, rot, mold and fungiprevention generally and as an ingredient in insect repellents andsprays. In the electroplating industry they may be employed as asubstitute for glycerine foots and in metal industries generally as ametal cleaning ingredient. The polymers may likewise be employed as aningredient in artificial flavors, non-spattering agent in cooking fats;anti-foaming agents; grinding aid in clinker cement; resin plasticlzerfor electrical insulation; ingredient in drilling fluids to controlthixotropy; and as a flotation agent in ore treating.

We claim:

1. A process for the preparation of solid polymers from glycois and1,3-dioxolane containing at least two groups having the structure--CH:OCH2CH2O which comprises reacting in solution under substantiallyanhydrous conditions from about 48 to 740 parts by weight of1,3-dioxolane per part by weight of a glycol 0ong up to and including 8carbon atoms in the presence of at least 0.001% by weight of an acidiccatalyst, after the solid polymer has been formed neutralizing thecatalyst and thereafter recovering the polymeric products.

2. A process for the preparation of a solid ethyleneglycol-1,3-dioxolane polymer which comprises heating in solution from 48to 740 parts by weight of 1,3-dioxolane per part by weight of ethyleneglycol with at least 0.001% by weight of an acidic catalyst undersubstantially anhydrous conditions and subsequently thereafterneutralizing the catalyst and separating from the reaction product theethylene glycol-1,3-dioxolane polymer.

3. A process for the preparation of a solid ethyleneglycol-1,3-dioxolane polymer which comprises heating in solution 740parts by weight of Lil-dioxoiane with 7.8 parts by weight of ethyleneglycol while in contact with 3.5 parts by weight of sulfuric acid as thecatalyst, neutralizing the catalyst with sodium methoxide to blue litmusand subsequently separating from the resulting product the solidethylene glycol-1,3- dioxolane solid polymer having a molecular weightof about 939.

. 4. A process for the preparation of a solid hexamethyleneglycol-1,3-dioxolane polymer which comprises heating in solution 740parts by weight of 1,3-dioxolane with 15 parts by weight ofhexamethylene glycol while in contact with 3.6 parts 11 by weight ofsulfuric acid as the catalyst, neutralizing the catalyst andsubsequently separating from the resulting product the solidhexamethylene glycol-1,3-dioxolane having a molecular weight of 694.

5. A solid glycol-1,3-dioxolane polymer produced in accord with theprocess of claim 1.

6. A solid glycol-1,3-dioxolane polym r produced in accord with theprocess of claim 2.

7. A solid hexamethylene glycol-1,3-dloxolane polymer produced in accordwith the process 01' claim 1.

DONALD J. LODER. WILLIAM F. GRESHAM.

REFERENCES crmn The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 996,191 Ach June 27, 19112,187,081 Hodgins Jan. 16. 1940 2,340,907 Sussman Feb. 8, 1944 2,360,477Dahle Oct. 17, 1944 2,366,737 L-oder et a] Jan. 9, 1945 2,366,738 Loderet al Jan. 9, 1945

1. A PROCESS FOR THE PREPARATION OF SOLID POLYMERS FROM GLYCOLS AND1,3-DIOXOLANE CONTAINING AT LEAST TWO GROUPS HAVING THE STRUCTURE-CH2-OCH2CH2O- WHICH COMPRISES REACTING IN SOLUTION UNDER SUBSTANTIALLYANHYDROUS CONDITIONS FROM ABOUT 48 TO 740 PARTS BY WEIGHT OF1,3-DIOXOLANE PER PART BY WEIGHT OF A GLYCOL CONTAINING UP TO ANDINCLUDING 8 CARBON ATOMS IN THE PRESENCE OF AT LEAST 0.0001% BY WEIGHTOF AN ACIDIC CATALYST, AFTER THE SOLID POLYMER HAS BEEN FORMEDNEUTRALIZING THE CATALYST AND THEREAFTER RECOVERING THE POLYMERICPRODUCTS.